Touch technologies are commonly used as input devices for a variety of products. The usage of touch devices of various kinds is growing sharply due to the emergence of new mobile devices such as Personal Digital Assistants (PDA), tablet PCs and wireless flat panel displays (FPD). Some of these devices are not connected to standard keyboards, mice or like input devices, which are deemed to limit their mobility. Instead there is a tendency to use touch input technologies of one kind or another. A stylus and/or finger may be used as a user interaction.
U.S. Pat. No. 6,690,156 entitled “Physical Object Location Apparatus and Method and a Platform using the same” and US Patent Publication No. 20040095333 entitled “Transparent Digitizer” both of which are assigned to N-trig Ltd., the contents of both which are incorporated herein by reference, describe an electromagnetic method for locating physical objects on a FPD and a transparent digitizer that can be incorporated into an electronic device, typically over the active display screen. The digitizer sensor includes a matrix of vertical and horizontal conducting lines to sense an electric signal. Positioning the physical object at a specific location on the digitizer provokes a signal whose position of origin may be detected.
U.S. Patent Application Publication No. 20040155871 entitled “Touch Detection for a Digitizer” assigned to N-trig Ltd, which is incorporated herein by reference, describes a digitizing tablet system capable of detecting position of physical objects and/or fingertip touch using the same sensing conductive lines. Typically, the system includes a transparent sensor overlaid on a FPD. The digitizer's sensor includes a matrix of vertical and horizontal conducting lines to sense an electric signal. Touching the digitizer in a specific location provokes a signal whose position of origin may be detected.
U.S. Patent Application Publication No. 20060012580, entitled “Automatic switching for a dual mode digitizer” assigned to N-Trig, which is incorporated herein by reference, describes a method utilizing different types of user interactions, e.g. electromagnetic stylus and touch, in a digitizer system. A method for palm rejection based on the size of the detected area of the touch is described.
U.S. Patent Application Publication No. 20060097991, entitled “Multipoint TouchScreen” assigned to Apple Computers, the contents of which is incorporated herein by reference, describes a touch panel having a transparent capacitive sensing medium configured to detect multiple touches or near touches that occur at the same time and at distinct locations in the plane of the touch panel and to produce distinct signals representative of the location of the touches on the plane of the touch panel for each of the multiple touches.